Keyboard



FIG. 1 is a front elevational view of a keyboard depicting our new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a perspective view thereof.

The broken lines which define the bounds of the claimed design form no part thereof. 

The ornamental design for a keyboard, as shown and described. 